Three-dimensional Coordination Research Articles

Fabrication of a novel mixed-valent copper-based coordination polymer as a fluorescent sensor for selective and efficient detection of multiple analytes

A novel three-dimensional fluorescent mixed-valent copper-based coordination polymer (CP), namely {[CuICuII4(triazol)6(bpta)2]Cl}n (Cu-CP), was synthesized hydrothermally in the presence of Cu(II) ion, 2,4,6-tri(1H-1,2,4-triazol-1-yl)-1,3,5-triazine (TTT), and 2,2′,4,4′-biphenyltetracarboxylic acid (H4bpta). The structure of the Cu-CP was studied using single-crystal X-ray diffraction (SCXRD) and powder X-ray diffraction (PXRD). Interestingly, the crystallographic data revealed that a part of Cu(II) ions were reduced in situ to Cu(I) ions as well as the nitrogen-containing ligand TTT was converted to triazol, which possessed excellent fluorescence characteristics as a transition metal ion with a d10 electronic configuration, prompting further investigation into the fluorescence sensing properties of Cu-CP. The results confirmed that Cu-CP exhibited excellent fluorescence performance which an outstanding candidate as a fluorescence sensor for Fe3+, Cr2O72−, CrO42−, MnO4− and nitrobenzene (NB), with a low limit of detection. For ethylene glycol (EG) detection, Cu-CP showed high-efficiency fluorescence enhancement across a range of temperatures. The underlying mechanism of fluorescence enhancement was investigated through comprehensive experimental studies.

A Sodium Metal-Organic Framework with Deep Blue Room-Temperature Phosphorescence.

It is a great challenge to manufacture room-temperature blue long afterglow phosphorescent materials adapted to environmental conditions. Herein, an Na-based metal-organic framework (MOF) was constructed using Na+ and 1H-1,2,4-triazole-3,5-dicarboxylic acid, which exhibits long-lived of 378.9 ms, deep blue and room-temperature phosphorescence, meanwhile possesses the visible blue afterglow for 3~6 seconds after removing excitation light source. The three-dimensional coordination bonds network provided by Na-based MOF protects the organic ligands intrinsic hydrogen bond network, resulting in the phosphor lifetime and residual color remaining unchanged in different gas atmospheres. Furthermore, first-principles time-dependent density functional theory reveals that the rigid Na-based MOF structure can limit the rotation and vibration of the room-temperature phosphorescent organic ligands. This limitation results in the suppression of non-radiative decay for both singlet and triplet excitons, promotes intersystem crossing, and increases the rate of radiative decay, ultimately achieving long-lived room-temperature phosphorescence.

Volumetric voltage imaging of neuronal populations in the mouse brain by confocal light-field microscopy.

Voltage imaging measures neuronal activity directly and holds promise for understanding information processing within individual neurons and across populations. However, imaging voltage over large neuronal populations has been challenging owing to the simultaneous requirements of high imaging speed and signal-to-noise ratio, large volume coverage and low photobleaching rate. Here, to overcome this challenge, we developed a confocal light-field microscope that surpassed the traditional limits in speed and noise performance by incorporating a speed-enhanced camera, a fast and robust scanning mechanism, laser-speckle-noise elimination and optimized light efficiency. With this method, we achieved simultaneous recording from more than 300 spiking neurons within an 800-µm-diameter and 180-µm-thick volume in the mouse cortex, for more than 20 min. By integrating the spatial and voltage activity profiles, we have mapped three-dimensional neural coordination patterns in awake mouse brains. Our method is robust for routine application in volumetric voltage imaging.

Impact of halogen⋯halogen interaction on the mechanical motion of a 3D Pb(II) coordination polymer of elusive topology.

Herein, we report the synthesis of a Pb(II) based three-dimensional coordination polymer (3D CP), [Pb(DCTP)]n (1) [H2DCTP = 2,5-dichloroterephthalic acid] with an unprecedented topology, which exhibits a photomechanical effect wherein crystals show jumping upon UV irradiation. The Pb(II) CP forms a type II Cl⋯Cl interaction, which weakens further upon UV irradiation to resolve the anisotropic mechanical strain. The work presented here could be a beacon to the nascent field of photoactuating smart materials.

A new three-dimensional barium(II) coordination polymer constructed from N,N'-bis(glycinyl)pyromellitic diimide: microwave-assisted synthesis, structure, Hirshfeld surface analysis and properties.

A new three-dimensional (3D) coordination polymer, namely, poly[diaqua[μ5-2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetato]barium(II)], [Ba(C14H6N2O8)(H2O)2]n, (I), has been synthesized by the microwave-irradiated reaction of Ba(NO3)2 with N,N'-bis(glycinyl)pyromellitic diimide {BGPD, namely, 2,2'-(1,3,5,7-tetraoxo-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindole-2,6-diyl)diacetatic acid, H2L}. The title compound was structurally characterized by single-crystal X-ray diffraction analysis and powder X-ray diffraction analysis, as well as IR spectroscopy. In the crystal structure of (I), the BaII ion is nine-coordinated by six carboxylate O atoms from five symmetry-related L2- dianions and one imide O atom, as well as two water O atoms. The coordination geometry of the central BaII ion can be described as a spherical capped square antiprism. One carboxylate group of the ligand serves as a μ3-bridge linking the BaII cations into a one-dimensional polynuclear secondary building unit (SBU). Another carboxylate group of the ligand acts as a μ2-bridge connecting the 1D SBUs, thereby forming a two-dimensional (2D) SBU. The resulting 2D SBUs are extended into a 3D framework via the pyromellitic diimide moiety of the ligand as a spacer. The 3D Ba framework can be simplified as a 5-connected hexagonal boron nitride net (bnn) topology. The intermolecular interactions in the 3D framework were further investigated by Hirshfeld surface analysis and the results show that the prominent interactions are H...O (45.1%), Ba...O (11.1%) and C...H (11.1%), as well as H...H (11.1%) contacts. The thermal stability, photoluminescence properties and UV-Vis absorption spectra of (I) were also investigated. The coordination polymer exhibits a fluorescence emission with a quantum yield of 0.071 and high thermal stability.

Monitoring the formation of infinite-layer transition metal oxides through in situ atomic-resolution electron microscopy.

Infinite-layer transition metal oxides with two-dimensional oxygen coordination exhibit intriguing electronic and magnetic properties due to strong in-plane orbital hybridization. The synthesis of this distinctive structure has primarily relied on kinetically controlled reduction of oxygen-rich phases featuring three-dimensional polyhedral oxygen coordination. Here, using in situ atomic-resolution electron microscopy, we scrutinize the intricate atomic-scale mechanisms of oxygen conduction leading to the transformation of SrFeO2.5 to infinite-layer SrFeO2. The oxygen release is highly anisotropic and governed by the lattice reorientation aligning the fast diffusion channels towards the outlet, which is facilitated by cooperative yet shuffle displacements of iron and oxygen ions. Accompanied with the oxygen release, the three-dimensional to two-dimensional reconfiguration of oxygen is facilitated by the lattice flexibility of FeOx polyhedral layers, adopting multiple discrete transient states following the sequence determined by the least energy-costing pathways. Similar transformation mechanism may operate in cuprate and nickelate superconductors, which are isostructural with SrFeO2.

Impact of Synthetic Variables on the Structural Diversity of TbIII-Carboxylate Frameworks: Gas Adsorption, Magnetism, and Organocatalysis Investigations.

In this work, three unique TbIII-carboxylate frameworks with the formula {[Tb2(OH)2(H2O)2(abtc)]·2H2O}n (1), {[Tb2(abtc)1.5(H2O)3(DMA)]·H2O}n (2) and {[Tb3(abtc)2.5(H2O)4]·H3O}n (3), each displaying structural variations, have been successfully synthesized by the solvothermal reactions of Tb(NO3)3·6H2O with the azo-containing ligand 3,3',5,5'-azobenzene tetracarboxylic acid (H4abtc) under varying conditions. Detailed single-crystal X-ray diffraction (SC-XRD) analysis manifested a remarkable diversity in these structures, demonstrating various coordination patterns of TbIII-metal nodes with the carboxylate groups of the organic linker, which contributed to the generation of intricate three-dimensional (3D) coordination networks with remarkable chemical resistance. Furthermore, frameworks 2 and 3, characterized by porous networks containing two and three independent TbIII-metal nodes, respectively, were both demonstrated to be efficient heterogeneous catalysts toward the cyanosilylation of imines under mild conditions with excellent reusability. In addition, direct current (Dc) magnetic susceptibility measurements conducted on frameworks 1, 2, and 3 indicated that there were obvious antiferromagnetic interactions among the TbIII-metal nodes, which suggests the involvement of intricate intra- and intertrimer exchange channels, adding another fascinating dimension to their physical properties.

Two three-dimensional coordination polymers as fluorescence probes for the detection of nitrobenzene, tetracycline, fluazinam and their application in green pepper

Two coordination polymers (CPs), [Zn5(L)2(phen)5](1) and [Cd2(HL)(2,2-bpy)(H2O)3](2), were synthesized by using 2′,3,3′,5,5′-Diphenyl ether pentacarboxylic acid (H5L), phenanthroline (phen), and 2,2′-bipyridine (2,2′-bpy) under hydrothermal conditions. The L5- ligand adopts the μ6-к2: к2: к1: к1: к1: к1 mode in 1 and the μ5-к2: к2: к2: к2: к1 mode in 2. Sensing experiments show that 1 and 2 are fluorescence probes with high sensitivity and rapid detection of nitro explosives, antibiotics, and pesticides. In order to verify the ability of 2 to detect FLU in actual samples, we performed a spiked recovery experiment in green pepper water. The spiked recoveries were 97.77–101.18 %. Interestingly, because H5L is not completely deprotonated in 2, there is abundant hydrogen bonding, which makes the fluorescence quenching rate higher and the detection limit lower. The possible fluorescence quenching mechanism of 1 and 2 can be explained by their UV–VIS absorption spectra and orbital energy levels.

(Invited) Selective Ammonia Separation Using Prussian Blue Analogues

Prussian blue analogues (PBAs) are a three-dimensional coordination polymer with iron and transition metals bridged with cyanide ligands, creating open-framework structures for hosting guest ions into interstitial sites. These sites can be occupied by cations via adsorption/desorption or intercalation/deintercalation, which has been widely utilized in developing separation processes and energy storage devices. Additionally, it has been well established that the size of the channel provides selectivity between monovalent cations based on their hydrated radii. Using these unique functionalities allows for selective ammonia recovery from wastewater. The feasibility of selective separation has been demonstrated using PBA-based electrodes that showed reversible and selective intercalation/deintercalation of NH4 + by cyclic operation. To enable continuous separation, we recently developed an electrochemically driven membrane process, where PBAs provided selective ion-conducting channels. An improved selectivity for NH4 + relative to Na+ was achieved using synthetic and domestic wastewaters, which was attributed to a thin layer of PBA created on the surface of a cation exchange membrane. These results collectively show that the use of PBAs for selective ammonia separation could lead to the development of efficient electrochemical processes for nutrient recovery.

Test-retest reliability and minimal detectable change in pelvis and lower limb coordination during running assessed with modified vector coding

The objective of this study was to evaluate the reliability of Modified Vector Coding in assessing the coordination and coordination variability of the lower limbs and pelvis during running and to determine the Minimal Detectable Change (MDC). Twenty-five healthy runners participated in a biomechanical analysis of treadmill running using a motion capture system. Modified vector coding was applied to assess the three-dimensional coordination among various pelvis and lower limb segmental couplings. Reliability was assessed using the Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM), MDC, and Bland-Altman analysis to ascertain measurement consistency, agreement, and the smallest clinically meaningful change that exceeds measurement error. The test–retest reliability for 33 of 42 segmental couplings analyzed was good to excellent, with ICC values ranging from 0.613 to 0.928 (p <0.05), which substantiates the robustness of modified vector coding in running biomechanics. However, nine couplings, particularly femur-tibia in the sagittal plane during midstance and foot in the frontal plane-tibia in the transverse plane during late stance, exhibited poor to moderate reliability. These findings underscore the need for cautious interpretation due to significant proportional bias (p <0.05). SEM and MDC provided insights into the precision and minimal clinically significant changes for each coupling. The findings confirm the reliability of modified vector coding for biomechanical analysis in running, with most couplings demonstrating consistent high reliability. Nevertheless, specific couplings should be interpreted with caution due to potential measurement errors. The application of MDC highlights the precision of modified vector coding in biomechanical analyses and emphasizes the importance of careful interpretation to improve clinical and research outcomes in running-related injuries.

Cationic Cu(II)-MOF with 6-C Uni-Nodal Network: Photocatalytic degradation of Rose Bengal dye and notable colorimetric recognition of TEA and 2,4-DNP

A newly synthesized metal–organic framework material, designated as {[Cu(Bimb)3]∙(H2O)2∙2I}n(1),was produced by synthesizing through a solvothermal process, where (Bimb) 1,4-bis[(1H-imidazol-1-yl)methyl]benzene and CuI were involved. Crystal properties were meticulously characterized using advanced techniques such as Scanning Electron Microscopy (SEM), Single crystal X-ray Diffraction (SCXRD), Powder X-ray Diffraction (PXRD), Energy Dispersive X-ray Spectroscopy (EDX) and Elemental Mapping. These analyses showed a strong three-dimensional coordination framework with exceptional thermal and structural stability. Furthermore, luminescence experiments carried out on (1) displays its exceptional capacity for sensing Triethylamine (TEA) and 2,4-Dinitrophenol (2,4-DNP) to the LOD of 3.16 × 10−6 M (0.319 ppm) and 4.6 × 10−7 M (0.084 ppm) respectively. Furthermore, a study conducted on (1), demonstrated that it possesses an outstanding photocatalytic degradation of Rose Bengal (96.72 %,), Methyl Violet (88.23 %,), and Bisphenol B (88.35 %), dyesrespectively. This indicates that (1) has a significant potential to address environmental contamination concerns due to the sensing and photocatalytic properties that it possesses.

Two Three-Dimensional LnIII Coordination Polymers Exhibiting Luminescent Sensing and a Magnetocaloric Effect.

Two lanthanide 3D coordination polymers [Ln2(L)4Cl2(H2O)4]n (Ln = Eu (1), Gd (2)) with quinoline-2-carboxylic acid (HL) as the ligand were successfully synthesized and characterized. Complex 1 exhibits a highly sensitive and selective luminescent response to 2,6-dipicolinic acid (DPA) in tap water and is virtually unaffected by interferences such as amino acids, aromatic carboxylic acids, and ions. With the addition of DPA, the luminescence intensity of complex 1 decreases rapidly to the naked eye. The detection limit of 1 toward DPA is 3.36 μM, which is much less than the infectious dose (60 μM) of the anthrax spores, indicating the high sensitivity of 1 to DPA. This study offers a basis for employing lanthanide complexes in real sample analysis, enabling direct and efficient detection of DPA with high sensitivity and specificity. Additionally, it is noteworthy that at a magnetic field strength of 7 T and a temperature of 3 K, the maximum entropy change for complex 2 attains a value of 23.56 J kg-1 K-1.

Functional Three-Dimensional Ce-Based Coordination Polymer: Synthesis, Structure, and Selective Sensing of Lysine and Arginine Based on the Luminescence Turn-On Effect

Functional Three-Dimensional Ce-Based Coordination Polymer: Synthesis, Structure, and Selective Sensing of Lysine and Arginine Based on the Luminescence Turn-On Effect

Luminescent coordination polymers with mixed carboxylate and triazole ligands for rapid detection of chloroprene metabolite

Chloroprene is a monomer widely used in the production of neoprene, and 1-hydroxy-2-butanone (1H2B) is one of the metabolites of chloroprene in urine, which can place a significant impact on human health by disrupting the normal structure and function of DNA. Herein, a three-dimensional Zn-based coordination polymer (1) and a two-dimensional Cd-based coordination polymer (2) were synthesized with mixed ligands of 2,5-furandicarboxylic acid (H2FDA) and 1,2,4-triazole (Htrz) and fully characterized. 2 exhibits excellent stability and superior sensing performance for 1H2B with fast response within 15 s, good recyclability and a detection limit of 9.24 μM. In addition, 2 demonstrates good selectivity in presence of main coexisting compounds in urine. In-depth investigations of the sensing mechanism revealed that the luminescence sensing is based on the competitive absorption and photoelectron transfer processes.

Synthesis, magnetic and fluorescence detection properties of four metal-organic frameworks based on imidazole carboxylic acid ligands

Four new metal-organic frameworks (MOFs), namely [M(HL)H2O]n (1–3) [M = Co (1), Ni (2), Cu (3)] and [Cd(HL)]n (4), were successfully structured based on imidazole carboxylic acid ligands [H3L = 5-(((1H-imidazol-2-yl)methyl)amino) isophthalic acid]. X-ray single-crystal diffraction analysis showed that MOFs 1–3 possess the same two-dimensional (2D) planar structure, while MOF 4 exhibited a three-dimensional (3D) coordination network. The magnetic test results showed that MOFs 1–3 have typically antiferromagnetic behavior. The sensing experimental showed that MOF 4 could be considered as a promising bifunctional fluorescent sensor for Cu2+ and Fe3+ ions with excellent selectivity and sensitivity, and the detection limit were 4.11 μM and 4.89 μM, with Ksv values of 1.37 × 104 M−1 and 1.24 × 104 M−1, respectively. The cycling experiment illustrated the good reusability of the material. In addition, the fluorescence quenching mechanism of MOF 4 was further explored in detail.

Two 3D Zn(II)/Co(II)-CPs as fluorescent sensors for turn-on and red-shift sensing of tryptophan and norfloxacin

Two three-dimensional (3D) coordination polymers (CPs), namely {[M(seb)(bbimb)]·3H2O}n (M = Zn for 1; Co for 2), were obtained via hydrothermal method using sebacic acid (H2seb) mixed with 1,4-bis(benzoimidazol-1-yl)butane (bbimb). The structures of 1 and 2 both display as 3D frameworks with a 5-fold interpenetrating dia topology. CPs 1 and 2 both exhibit excellent luminescent properties and good water stability. Fluorescence sensing experiments demonstrate that 1 and 2 both can selectively detect tryptophan (Trp) and norfloxacin (Nor) in aqueous solution through turn-on and red-shift effect with remarkable anti-interference ability and low detection limits. The limits of detection (LOD) toward Trp-and Nor are 0.07 μM, 0.08 μM for 1 and 0.41 μM, 0.11 μM for 2. In addition, theoretical calculations and different detection methods were utilized to thoroughly investigate the potential sensing mechanisms for Trp-and Nor. Importantly, 1 and 2 represent two rare examples for sensing both Trp-and Nor via turn-on and red-shift effects. The fluoresence test films of 1 and 2 were prepared which can detect Trp-and Nor quickly with naked eye.

Solvent control of dimensionality in titanium aryloxide coordination polymers prepared from 4,4′-bis(hydroxyphenyl)sulfide

The crystal and molecular structures of three covalent metal–organic network (CMON) materials synthesized from titanium (IV) isopropoxide and the Bisphenol-A analog 4,4′-bis(hydroxyphenyl)sulfide in three different solvents have been determined. The structures of the one-dimensional chain coordination polymer [trans-Ti(μ-O:O’-OC6H4SC6H4O)2(C5H5N)2]n (1) obtained from pyridine and the two-dimensional sheet coordination polymer {[Ti2(μ-O:O’-OC6H4SC6H4O)2(μ2O:κO’-OC6H4SC6H4O)2(C4H8O)2]∙(C4H8O)y}n (2) from tetrahydrofuran both contain octahedral titanium (IV) coordination geometries, whereas the doubly interpenetrated three-dimensional coordination network [Ti2(μ-O:O’-OC6H4SC6H4O)2(μ2O:κO′-OC6H4SC6H4O)2]n (3) synthesized from benzene contains trigonal bipyramidal titanium (IV). Each material has been characterized by single crystal and powder X-ray diffraction, elemental analysis, and by 1H NMR quench when it contains more than one organic component.

Synthesis, Characterization, Investigation of Catalytic and Thermal Properties of Three-Dimensional and Layered Copper Organodiphosphonate Coordination Polymer

Bu çalışmada, (1,4-fenilenbis(metilen))bis(fosfonik asit) ligandı (H4L) ve katmanlı yapıya sahip bakır organodifosfonat polimeri, [Cu2(C8H8O6P2)(H2O)2]n (1), sentezlenmiştir. Sentezlenen bileşiklerin yapıları çeşitli spektroskopik ve analitik yöntemler kullanılarak karakterize edilmiştir. Tek kristal X-ray analizi sonucunda 1 nolu bileşiğin üç boyutlu ve sütunlu tabaka yapısında organik/inorganik katmanlardan oluştuğu gözlenmiştir. Monoklinik kristal sistemi ve P21/c uzay grubunda olan bileşik 1'in hücre parametreleri a = 10.8142(9) Å, b = 7.5839(6) Å, c = 7.3991(6) Å, V = 606.26(9) Å3 ve Z= 4'tür. Polimer zinciri içinde her bir bakır atomu toplam beş koordinasyona sahip olup kısmen bozulmuş kare piramit geometridedir. 1 polimerinin heterojen katalitik aktivitesi ve termal özellikleri incelenmiştir. TG analizi sonuncunda katalizörün 200 ᵒC sıcaklığa kadar termal kararlılığa sahip olduğu gözlenmiştir. TBHP kullanarak 60 ᵒC sıcaklıkta ve 12 saat sonunda %92.37 timol dönüşümü meydana gelmiştir.

An anionic In(III)-MOF for efficient adsorption of CO2 from CO2/N2 mixture and dye removal

Efficient adsorption of CO2 and dye molecules is crucial for reducing carbon emission and environmental pollution. Metal-Organic Frameworks (MOFs) are considered to be the ideal candidates for gas adsorption material because of their designability. In this work, a new In(III)-MOF (HBU-22) was synthesized by the reaction of a tetracarboxylic acid ligand (H4L, 9,9′-bicarbazole-3,3′,6,6′-tetracarboxylic acid) with In3+ ions, which shows a three-dimensional (3D) coordination network. The saturated adsorption capacity of CO2 and N2 are 21.11 cm3‧g−1 and 0.66 cm3‧g−1 at ambient condition (298 K, 100 kPa). And the higher IAST selectivity of CO2/N2 (v/v, 15:85) reaches 347.37, exceeding that of most MOFs. Furthermore, it can also capture C2H2 with the maximum uptake of 42.80 cm3 g−1. More interestingly, HBU-22 as an anionic framework, which can selectively adsorb Rhodamine B (RhB) within 250 s with the maximum adsorption capacity of 105.04 mg‧g−1. Further studies show that higher gas adsorption capacity is mainly related to the larger Qst of the gas, while its adsorption of Rhodamine B (RhB) is mainly due to ion exchange mechanism.

Fabrication of Energetic Metal-Organic Frameworks: Potassium 5-Carboxylato-3,4-Dinitropyrazole and Potassium 5-(Hydrazinecarbonyl)-3,4-Dinitropyrazole.

Energetic materials have been widely applied in civil and military fields, whose thermostability is a key indicator to evaluate their safety levels under severe conditions. Herein, two novel energetic metal-organic frameworks (EMOFs), namely, 4 and 6, were experimentally obtained and comprehensively characterized. The two EMOFs both possess unique three-dimensional (3D) coordination structures. With a high crystal density of 2.184 g·cm-3, EMOF 4 exhibits outstandingly superior thermostability (onset: 290 °C; peak: 303 °C), while EMOF 6 features onset and peak decomposition temperatures of 220 and 230 °C. The calculated energetic parameters of 4 and 6 are as follows: detonation velocity: 8731 m·s-1 and 8294 m·s-1; detonation pressure: 26.5 and 26.4 GPa. Compared to EMOF 6, EMOF 4 features high energy, excellent thermostability, and low mechanical sensitivities, which should be partly attributed to more plentiful coordination interactions. More coordination bonds are conducive to strengthening the EMOF framework, which needs much more energy to collapse, thereby maintaining higher thermal stability. The above favorable characteristics not only indicate EMOF 4 has a promising future in applications as a thermostable explosive but also provide an effective and feasible strategy for developing novel heat-resistant energetic materials via reinforced frame structures of EMOFs.